config: add --source option to include source of value
Showing the source of each config option is quite useful and not
something the user should have to reach for the `--debug` flag for.
I updates documentation and tests, except for one place in
`test-hgrc.t` where I thought the test might have been intended to
also test that `--debug` results in `ui.quiet` etc being test.
Differential Revision: https://phab.mercurial-scm.org/D10668
{
// Enforcing
"eqeqeq" : true, // true: Require triple equals (===) for comparison
"forin" : true, // true: Require filtering for..in loops with obj.hasOwnProperty()
"freeze" : true, // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
"nonbsp" : true, // true: Prohibit "non-breaking whitespace" characters.
"undef" : true, // true: Require all non-global variables to be declared (prevents global leaks)
// Environments
"browser" : true // Web Browser (window, document, etc)
}